When our friends John, Graham and Myrddyn told us they had discovered a new mountain we expected to be setting off immediately to climb it (and probably wading through six foot snow drifts to attain the goal). But it isn't necessary - we've already climbed it!

We didn't know it was a two thousander then of course, but in May 1998 we did a North Pennines backpack. Starting from Appleby we walked via Dufton up High Cup Nick and camped on Backstone Edge. On Day 2 we continued over Knock Fell, Great and Little Dun Fells, Cross Fell, Melmerby Fell and Fiends Fell and camped on the summit of Black Fell. Day 3 was over Thack Moor (See picture of John by the trig point), then it was on to Croglin and Armathwaite and back by train

Article by John Barnard, Graham Jackson and Myrddyn Phillips

New 2,000ft mountains are somewhat of a rarity as so few have been 'discovered' since John and Anne first published their books to 'The Mountains of England & Wales'. There was a spate of new entries to the Welsh listing in the 1990's, but for England those new 2,000ft mountains are a rarer breed, something to be treasured when found.

These 'new' English mountains consist of only two in number. The first was Birks Fell which was optically surveyed by the fledgling team of John Barnard and Graham Jackson with the second being Honister Crag in the Lake District. Just two 'new' English mountains – a rare breed indeed!

Would a third 'hill' enter the hallowed ranks? This is the question the team of G&J Surveys planned to answer and the 'hill' that was now pushing its way toward the top of our survey list was Thack Moor.

This fell is situated in that great swathe of bleak and wonderful landscape known as the Pennines and is positioned above the small village of Renwick with its grid reference being NY611462. Thack Moor has a current map height of 609m, which is very close to that all important qualifying height of 2,000ft (609.60m).

With our sights firmly on Thack Moor we first visited the fell in August 2012. An approach from Renwick up the fells southern slopes using a vehicle track that slowly peters out to a green track and narrow path gave us good access to the fells upper slopes. The last few minutes are on the steepest ground and with us carrying all necessary surveying equipment of a level and staff, tripod, Leica Geosystems 530 GPS receiver and pole; it proved a slow last plod to the solid stone wall that follows this fell's summit ridge.

An Ordnance Survey Triangulation Pillar is positioned just on the southern side of the ridge wall. Our first objective using the level and staff was to determine if the high point of Thack Moor was on the southern or northern side of the wall. We soon determined that the ground on the northern side is in fact the higher. We then laid a series of flags following the high ground in a line at the base of the wall and parallel to it about six metres away. By placing the staff at each flag and reading the relative height with the level we could narrow the high ground down to a small area. This procedure was then repeated until the very highest point of Thack Moor was found.

Whilst doing this, the dark grey clouds that had been building up to the west sped our way as the first of the forecast localised heavy showers descended upon us. However, we soon positioned the Leica 530 over the high point of Thack Moor and hunkered down behind the wall for the two hours of data collection.

Once our vigil was completed we continued over to Watch Hill and eventually descended back to the car at Renwick pleased with our efforts and happy in the knowledge that we had paid our visit to Thack Moor and surveyed its highest point. However, once the data were processed, the result was of so much interest we consulted with Mark Greaves, Geodetic Analyst at Ordnance Survey. Mark's advice was to re-visit and gather an additional four hours of summit data.

Autumn soon turned into winter and the thought of spending four hours and more on a bleak Pennine 'hill' in the depths of winter did not fill us with joy, so we waited until the onset of better weather and the longer daylight hours of early spring. The opportunity to re-visit Thack Moor came on the 3rd March and along with Bob Smith, the Editor of the Grough website who was accompanying us for a feature article, we again ascended from the village of Renwick. Conditions for this second survey were almost perfect as no rain was forecast; the cloud base was high, visibility good, with only an occasional wisp of light breeze.

However, once over the summit ridge wall we encountered a bank of thick and solid wind-blown snow that had accumulated against the wall and was stretching out toward the high point of the fell. Having previously taken ten figure grid references with hand held GPS units of the summit position we could pinpoint this on the ground to within a few metres. We then spent some time clearing a section of ground of its snow in the position where the summit is. Thankfully as the high point was just on the edge of the snow we could soon determine again by level and staff the very highest point of Thack Moor. We positioned our new Leica GS15 over it and started our long four hour vigil. After what seemed an eternity the four hours had elapsed and the equipment was then switched off, dismantled, packed away and we finally descended to the friendlier climate of the valley below.
The two data sets from our surveys in August 2012 and March 2013 were sent to Mark Greaves at Ordnance Survey who kindly processed them. But what of the result? Would Thack Moor join the elevated ranks of 2,000ft mountains and become only the third 'new' English mountain to enter John and Anne's list? The result confirmed by Ordnance Survey is that Thack Moor is 609.62m in height. So, the 'hill' becomes a mountain by just 2cm or in imperial terms no more than ¾ of an inch!